Israeli police have arrested an Israeli-Jewish teenager as the main suspect in a string of anti-Semitic bomb threats in the United States.

The US-based Anti-Defamation League said more than 150 bomb threats had been made against schools and Jewish community centres since January 9.

It said they were spread across 37 states and two Canadian provinces.

Police spokesman Micky Rosenfeld described the suspect as a hacker from southern Israel who made dozens of threatening calls since January claiming to have placed bombs in public places and private companies.

"He's the guy who was behind the JCC threats," Rosenfeld told reporters, referring to the dozens of anonymous threats phoned into Jewish community centres in the US over the past two months.

The FBI, which had taken part in the investigation, confirmed the arrest but had no other comment.

Rosenfeld said police searched the man's house in Ashkelon in southern Israel on Thursday morning and discovered antennas and satellite equipment.

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"He didn't use regular phone lines. He used different computer systems so he couldn't be backtracked," he said.

Rosenfeld added the man had called Delta Airlines in February 2015 and made a false threat about explosives aboard a flight from JFK airport in New York. The threat allegedly led to an emergency landing.

Israeli media identified the 19-year-old as an American-Israeli dual citizen and said that he had been found unfit for compulsory service in the Israeli military.

The threats led to evacuations of the buildings, upset Jewish communities, and raised fears of rising anti-Semitism. They were accompanied by acts of vandalism on several Jewish cemeteries.

Galit Bash, the suspect's lawyer, said a medical condition was the root of problem.

"My client ... suffers from a very serious medical problem, a problem that may affect his behaviour, his ability to understand right and wrong," Bash told Reuters news agency.

Last month, the White House denounced the phone calls and rejected "anti-Semitic and hateful threats in the strongest terms".